Off-by-one error in the encodes function in pack.c in Ruby 1.9.3 and earlier, and 2.x through 2.1.2, when using certain format string specifiers, allows context-dependent attackers to cause a denial of service (segmentation fault) via vectors that trigger a stack-based buffer overflow.

Affected: Ubuntu:14.04:LTS: ruby1.9.1, Ubuntu:14.04:LTS: ruby2.0

Will Wood discovered that Ruby incorrectly handled the encodes() function. An attacker could possibly use this issue to cause Ruby to crash, resulting in a denial of service, or possibly execute arbitrary code. The default compiler options for affected releases should reduce the vulnerability to a denial of service. (CVE-2014-4975)

Willis Vandevanter discovered that Ruby incorrectly handled XML entity expansion. An attacker could use this flaw to cause Ruby to consume large amounts of resources, resulting in a denial of service. (CVE-2014-8080)